Device for sharpening picker teeth



Dec. 12, 1939. L. s. EAsTMAN DEVICE FOR SHARPENING PICKER TEETH Filed April 13, 1958 LESTER 5. sTMn/v 5% C M1 o I (libwww/u Patented Dec. 12,1939

UNETED STTE rArsNr orties v 2,183,348 DEVICE FOR SHARPENING PICKER TEETI-I Lester S. Eastman, Worcester, Mass.

Application April 13, i938, Serial No. 201,748'

2 Claims.

This invention relates' to a device for sharpening picker teeth and more particularly for truing and sharpening the revolvable teeth of a machine used for reducing'to pickered stock various materials, such as rags or Waste of cotton, woolen, silk or rayon.

A machine of this class usually comprises an endless belt or rotatable drum having a large number of slender, closely spaced iron teeth or pegs projecting radially from its periphery. The drum is so arranged that the teeth pass substantially vertically across the end of an open chute; and the rags, jute bagging, burlap waste, or other material to be picked apart, is fed by one or more corrugated rollers and an endless belt through the chute and held in contact with the rapidly revolving teeth and thus torn apart to form a soft, iiuffy mass of pickered material suitable for being spun into thread for a new weaving operation. It is found that these teeth wear away in the course of time, and in particular they become rounded at their ends and do not present the sharp and chisel like edges which are best suited for tearing the waste apart. It has been customary, heretofore, for the machine operator to hold an abrasive rubbing brick against the ends of the rapidly revolving teeth or picks and thus abrade and true the same. This operation requires skillful handling of the rubbing brick to avoid the operator being injured; and it is found that it is not usually possible to get'all of the teeth sharpened `properly or trued to the same height and degree of sharpness, so that some teeth will remain unsharpened below the plane of yother teeth and thus create inefficient operation.

This is a tedious and time wasting operation and thus takes the machine out of commission and prevents its being used efliciently during a needed full time service.

A primary object of this invention is to overcome these diiculties and to provide a device which will serve for truing and sharpening the picker teeth or pins to a uniform condition and the same height, and which may be easily adjusted and operated to give desired eflicient results with the minimum waste of time and effort.

A further object of the invention is to provide an abrasive stone and support therefor which may be removably andvreplaceably utilized with the supporting and feeding mechanism and then readily replaced by a new unit when the first has ,become worn out. Further objects will be apparent in the following disclosure.

` Referring to the drawing which illustrates one `embodiment, of this invention: f

Fig. 1 is a perspective view of my abrading device;

Fig. 2 is an enlarged vertical sectional View thereof, together with a fragmentary detail of a portion of a revolving drum with its picker teeth; 5v

Fig. 3 is a rear end elevation of the device, showing the rag feeding chute in dotted outline and the picker drum of the machine broken away; and

Fig. 4 is a fragmentary perspective View ci the abrasive stone and its holder.

The rag or waste picker usually comprises a cylindrical drum It suitably mounted on a central support Ii and a spindle and revolved by power mechanism, as required. Mounted on the 15 outer cylindrical surface of the drum lil are a set of wooden boards l2, to which are suitably secured the picker teeth It. These teeth may be steel pins, somewhat over 1 inch in length and tapering from about 1A; inch diameter at the end to 1 5.; inch at the base and having their circular ends formed as substantially plane faces arn ranged in staggered rows in a closely spaced arrangement, such as 1/2 inch apart, so that the rags or waste fed thereto will be caught by the teeth and torn into individual fibers.` The boards l2 are suitably secured to the drum it, as by means of the bolts I6 which have heads l1 overlapping the adjacent sides of the closely positioned boards. The picker teeth I4, only a portion of which are shown in Fig. 3, pass substantially vertically in front of the open ended channel formed by the trough I8 and thusv engage and tear the waste as it is moved through that trough by a vpair of corrugated feeding rollers.

In order to sharpen the ends of these iron teeth, I provide a device which comprises a substantially stationary but adjustable abrasive stone 2li of such dimensions, shape and arrangement that it may be held and nely adjusted into abrading contact with the ends of the teeth. The stone is preferably a long narrow block of abrasive having its effective abrasive face arranged parallel with the drum axis, and it is preferably so mounted that it may be fed towards the teeth by a line motion device and adjusted to insure grinding the teeth to uniform sizes. The adjustments may include either or both of two fean tures, one for sliding or moving the stone laterally and the other for swiveling it about a vertical axis so as to move either end towards the teeth and bring the face of the stone into parallelism with the drum axis.

, The preferred form of this device comprises a metal platform 22 having a dovetailed slideway 55 23 within which is slidably mounted a plate or slide 24. This slide carries the abrasive stone 20 adjustably mounted on its inner end. The abrasive stone 28, which may be made in one or more pieces, is preferably cemented and xedly secured in a U-shaped holder 28 by means of a layer of Suitable cement 29, so that the holder and the stone are substantially integral. The holder 28, which need not extend throughout the length of the stone, as illustrated in Fig. l, is in turn mounted for sliding laterally or parallel with the drum axis to compensate for uneven wear on the stone. To that end, it is made to slide in a substantially U-shaped slideway 32 formed of the upper and lower plates 33 connected together by the back 34 and which may be fashioned as a single U-shaped casting. This holder 32 has aligned holes through its upper and lower plates and near its center portion which serve as bearings for the pivot bolt 35, so that the stone 28 may be swiveled into proper contact with the picker teeth. The bolt 36 is suitably secured in a countersunk hole in the slideway 24. Two further bolts and nuts 38 are likewise mounted in holes in the plate 24 and project through elongated arcuate slots 40 (Fig. 1) in the U-shaped slideway 32, which aid in holding the latter in an adjusted position for a delicate adjustment thereof. Two angle irons 42 are xed on the top of the slide plate 24, and bolts 44 threaded through the vertical portions of these angle irons engage the wall 34 of the slideway 32. Thus, when the wing nuts on the bolts 38 are loosened, the bolts 44 may be employed for a very delicate pivotal adjustment of the abrasive plate 28. Thereafter, the nuts on the bolts 38 may be clamped in position and serve to prevent further pivotal move ment of the abrasive stone 20 during the grinding operation. This construction for swiveling the stone may be omitted, if desired.

In order to move the slide 24 and feed the abrasive stone towards the picker teeth, an L- shaped bracket or angle-iron 45 may be suitably secured, as by means of cap screws, to the frame 22. A screw 45, which has a hand wheel 4'! on its outer end, is rotatably fitted within a bearing hole in the upper end of the bracket 45 and a collar on the screw prevents endwise movement. The screw 46 is threaded into an upright arm 5D on a further L-shaped bracket which is secured as by cap screws to the top slide 24. Thus by turning the hand wheel 4l', the screw 46 will serve to move the arm 5D and the slide 24 back and forth as required. By this means, one may feed the abrasive stone 2U forward as the picker teeth are ground away and thus provide the necessary grinding contact.

A further feature of the preferred form of the device comprises mechanism for adjusting and for reciprocating the abrasive block 28 laterally or parallel with the aXis of the drum i8, so that a given peripheral row of picker teeth may not be permitted to wear a groove into the abrasive stone and the grinding action will be made more uniform and the stone will be worn to the same extent throughout its surface. This is readily effected by means of a pinion 52 mounted on the end of the shaft 53 pivotally mounted in the upper end of a bracket 54, which is in turn secured to the top of the slide 24. A hand wheel 55 pinned to the shaft 53 serves to turn this shaft and the gear 52. The inner end of the shaft 53 is removably mounted in a split bearing block 56 suitably secured on the top of the U-s'naped slideway 32. This slideway has a slot 51 through its upper plate 33, and the pinion 52 projects through that slot into contact with rack bar teeth 58 on the upper side of the stone holder 28, as illustrated particularly in Fig. 4. The U- shaped holder 28 is arranged to slide into the end of and within the slideway 32. To this end, the top portion of the holder 28 may be provided with an upstanding key 60 into which the teeth 58 are cut. This key 68 fits within a U-shaped groove 62 extending the entire length of the under side of the top plate 33 of the holder 32, A further key 63 on the bottom of the stone holder 28 aids in guiding the reciprocating holder. Either or both of these keys may be omitted, and equivalent construction employed for holding the stone and its holder in position.

The abrasive stone may be made of suitable material, such as silicon carbide or crystalline alumina abrasive bonded by a standard bond. I have found that a stone which is well adapted for this purpose is made of 60 grit crystalline alumina abrasive bonded by ceramic vitried material to a grade of M on the Norton scale of hardness. Wide variations may, however, be made in the composition and structure of the abrasive stone.

It is desirable that the stone 20 be rigidly po sitioned in the holder 28 and in proper location for the intended use. Hence, it is preferable to fix these parts together permanently in the factory where proper xtures are available for the purpose. Then, when the stone has become worn away, the stone and its holder are to be discarded and a new set substituted therefor. Various modifications in the construction of this set may be made, but it is preferred that the holder be provided with rack bar teeth to effect its reciprocation, and a key which locates and guides the holder. It will be appreciated that a vertical ange on the outer edge of either or both of the plates 33, which is arranged to engage the front edge face of holder 28 will serve for the purpose and that the front edge face of the holder will then be arranged parallel with the drum axis so that it will serve as a key and guide the holder. Other equivalent keying constructions may be used. If desired, the key and the keyway may be interchanged, within the scope of this invention, and the term key is to be construed broadly as referring to either of these cooperating parts. Also, the rack bar teeth 58 may be cut for the entire length of the upper key 6D, so that the parts may be readily assembled by sliding the holder 28 directly into position. If the teeth 58 are located only in the required position for cooperation with the gear 52, then the parts may be assembled by removing the bearing cap 56 and swinging the shaft 53 upwards slightly, or by so constructing the parts that the gear may be removed. Numerous other constructions will satisfy the purposes of my invention.

The operation of the device will be readily apparent in view of the above disclosure. The stone unit is inserted endwise into the slideway 32. The stone 28 may have its operative end cut on a bevel as illustrated, or it may have a vertical surface and be permitted to wear away during grinding until it automatically assumes the shape shown in the drawing. The carrier 22 is mounted on the side walls of the chute I8, and it may be suitably clamped thereto, as by means of the swiveled clamping blocks 64 which are suspended by bolts 65 beneath the carrier 22 and may be swung into position to interlock with the outwardly projecting top flanges of the chute I8.

Hence, whenever the picker teeth I4 are to be sharpene-d, the abrasive device is slid along the top rails of the chute I8 and clamped into position with the abrasive block almost in contact with the picker teeth. Then, by means of the hand wheel 41 the slide 24 is moved forward until the stone just touches the teeth. The stone may also be swiveled about its central pivot 36 by means of the adjusting screws 44. rIlhe stone is brought into sparking contact with the rapidly revolving picker teeth and grinding proceeds. The stone may be moved back and forth laterally by means of the hand wheel 55. This movement may be continuous or intermittent, but suicient to insure a uniform wear on the abrasive stone and a similarly uniform grinding of the ends of the picket teeth. As the teeth wear away, a slight inward feed of the slideway 24 will serve to effect the necessary adjustment and insure that all of the teeth are of the same height and that their outer ends are planes which are substantially perpendicular to their axes. This construction, therefore, permits sharpening the teeth in situ without removing them from the drum and while the machine is running normally. Hence, there is very little loss of time during which the machine maynot be used for its pickering operation.

Various modifications may be made in the c onstruction and arrangement of the parts as will be readily apparent in view of the above disclosure, and it is intended that the claims shall be given a broad interpretation therefor.

I claim:

1. An attachment for a picking machine having a feeding chute and a revolving drum provided with picker teeth comprising a support, means for removably securing the same on the chute, a substantially stationary abrasive stone having an extensive face arranged to engage a plurality of picker teeth, a slidemovable on the supports towards and from the teeth, means for adjusting the same, a member pivotally mounted on said slide which has a slide way substantially parallel with the drum axis, a second slide carrying the stone which is movable in the slide way, means for moving said second slide to re-` ciprocate the stone across the teeth and means for pivotally adjusting the slide way member so as to swing the stone into uniform abrading contact with the teeth.

2. An attachment for a picking machine having a feeding chute and a revolving drum provided with picker teeth comprising a support, means for removably securing the same on the chute, a substantially stationary abrasive stone having an extensive face arranged to engage a. plurality of picker teeth, a slide movable towards and from the teeth, means for adjusting the same, a pivotally mounted member which has a slide way substantially parallel with the drum axis, a second slide carrying the stone which is n 

